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Showing posts from April, 2018


Found back my old  PYE PF2 UB    pocket  70cm portofoon  produced 1970 --75
Once used in our local DX  warning net  432.775  433.525 back in the  previous millennium  80 ties

Still worked after all the years.  Portofone  is huge compared with modern sets
0.5W - 0.8W  out

There is a PYE museum web-page
Interesting to look at the well  designed Technics inside
It comes from Cambridge so it is good beyond doubt ...

Extreme power / battery efficient   RX/standby  pulsing 1-2mA  duty cycle 10%  at 13.6V
The TX takes only 160mA  at  500mW out  at this point it can beat  modern devices.
The Battery voltage is 15V   it can safely work on  motor bike or car power  voltage  13.6V  and plus
Featuring an economizer circuit  that is a pulsing  supply for RX   duty cycle 10%
to check for incoming signals. Once a signal is detected the RX will turn100% on
I know the old Icom IC2E 144 FM device  being also very power efficient   but this porto beats them …


Fantastic signals received and worked at PI9CAM Dwingeloo   today at 1296.025 CW
EME contest with straight-key and Excel logging ...
I am spoiled with N1MM logging and keying
PA2DW  at the key picture below is a straight key man former marconist.

WSPR 12 hours

TimestampCallMHzSNRDriftGridPwrReporterRGridkmaz 2018-04-13 23:44  PA0O  5.366136  -18  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-13 21:24  PA0O  5.366135  -20  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-14 00:36  PA0O  5.366136  -21  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-13 22:38  PA0O  5.366136  -20  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-14 01:24  PA0O  5.366136  -18  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-14 00:56  PA0O  5.366136  -21  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-13 21:54  PA0O  1.838034  -24  0  JO33hg  1  DP0GVN  IB59uh  13835  186  2018-04-14 01:42  PA0O  3.594034  -27  0  JO33hg  1  WA3CDL  EL88ri  7467  287  2018-04-14 03:50  WD4AH  3.594155  -16  0  EL89rt  2  PA0O  JO33hg  7344  41  2018-04-14 00:50  WD4AH  3.594159  -15  0  EL89rt  2  PA0O  JO33hg  7344  41  2018-04-14 02:16  KN8DMK  3.594090  -18  0  EM89oo  2  PA0O  JO33hg  6556  44  2018-04-14 01:58  KN8DMK  3.594089  -21  0  EM89oo  2  PA0O  JO33hg …

QRM QRM QRM in a would be low noise QTH

28.074MHz  FT8 band  with S5 noise

today ALL BANDS  are polluted with QRM  0 to 1300MHz

S5 Noise 28MHz S7 21 MHZ
whole spectrum is  30dB and higher noise plus carriers  digital smog
 50MHz  30dB noise from the Solar EDGE broadband transmitter

AT  Dutch Telecom say it is within the legal limits
They could not even detect it on their mobile equipment
It is legal to make RF smog as long as the GSM traffic and other services  is just good enough.

23cm 1.3GHz   never ending s7 QRM cracking from direction S-W
28 MHz complete covered with S5 sm noise day and night
50MHz  noise raise to 30dB  in the direction of SOLAR EDGE  system at 50m

from almost 0 to  at least 150 MHz  every 200kHz  a group off digi trash carriers

I have to investigate this myself
The  Agentschap Telecom can only detect radio interference that exceed levels of 50dB
on normal radio HAM receivers 

5362kHz Stanag  signal from Denmark 9+60bd !!

i am not the only HAM negative…

SPF5189z Low noise preamp 23cm

14-4-2018 updated

Above the low noise  preamp 50 - 4GHz    ebay  6€

Tested  2 small porto antennas
1 Baofeng UV antenna left   2nd best signal on PI2NOS
2 eBay DIAMONDSRH805S  wide band 144/432/1200  it works for its size as expected
3 piece of wire :   best signal in the setup...

Unit under test at workbench.
It was stable  50mA  at 5V   few days,  but sudden the current went up to 100mA
And i could  no longer adjust it with the negative bias Voltage.
The - Voltage went to zero and the SPF input port became low Z.
This SPF5189z was broken  no oscillations, no input overload just it broke while i was receiving the PI2NOS 430.125 using a small antenna at the workbench.

The specs of  SPF5189z  say it has an internal circuit  regulating the bias current.
Replaced . again   with an other of the 5 spare SPF i have.
The new one again could be adjusted at 50mA  5V 
The current raises to 150mA  when removing the  negative gate voltage.
Where is that internal bias circuit ?
I suspect  eBay …

474.2 kHz 630m

the last 630m T.A. decode was  end of March


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